Eurogamer did a little digging and found that, back on April 16, Community Coordinator Jason Leavy said there would be an option of using a keyboard for chatting on consoles. A day later though, he apologized for the confusion and revealed keyboard text chat support isn’t actually happening:

We wanted to provide an update on keyboard support for the console version of ESOTU.

Unfortunately, the message I posted in this thread yesterday was based on our development plans from earlier in the year, which included keyboard support for chat. However, keyboard support for chat is not something that will be available for the console version of the game. You will be able to use a keyboard for text entry in areas such as guild naming, etc., but not for chatting.

Mouse support is not planned for the console version of ESOTU.

Meanwhile, on the official support page for The Elder Scrolls Online, it says, “Console versions of the game will also provide limited input by USB-connected keyboards for features not already supported by voice chat or controller input.”

To get a clear-cut answer on the situation, Eurogamer reached out to Game Director Matt Firor, who confirmed The Elder Scrolls Online communication for consoles is based around voice chat. “That being said,” he added, “we are looking into implementing a ‘quick chat’ system, and when we have more news to share, we’ll let you know.”

The Elder Scrolls Online: Tamriel Unlimited releases on June 9, 2015 for the PlayStation 4 and Xbox One in North America and Europe.